[firebase_messaging] adding support for deleteInstanceId and setAutoInitEnabled

[ffeu]

fix flutter/flutter#20627

If an app has a basic flow with user login and logout AND receives notifications based on the logged user, the logout method needs to delete the current instanceID connected to Firebase Cloud Messaging. Otherwise, the unauthenticated app (after the user logs out) will still receive notifications from the previous logged user.

As deleteInstanceId might automatically recreate a new one, autoInitEnabled and setAutoInitEnabled must be provided as well.

Note: Firebase Java plugin uses deleteInstanceId ("Id"), in this Dart implementation deleteInstanceID ("ID") is being used.

[ffeu]

Hi @kroikie , can you please take a look at this one?

Note: the only way I could manage the Java deleteInstanceId to work was using a Thread, as described here.

[kroikie]

Could you verify explicitly here that true and false are called here?

verify(mockChannel.invokeMethod('setAutoInitEnabled', true));

[ffeu]

Is that what you mean?

    // assert that we havent called the method yet
    verifyNever(firebaseMessaging.setAutoInitEnabled(true));

    firebaseMessaging.setAutoInitEnabled(true);

    // assert we called the method with enabled = true
    verify(mockChannel.invokeMethod('setAutoInitEnabled', true));

    // assert that enabled = false was not yet called
    verifyNever(firebaseMessaging.setAutoInitEnabled(false));

    firebaseMessaging.setAutoInitEnabled(false);

    // assert call with enabled = false was properly done
    verify(mockChannel.invokeMethod('setAutoInitEnabled', false));

What I really would like to do is to call autoInitEnabled() to check its value after calling setAutoInitEnabled, but as both method implementations lie on the plugin, we don't have access on testing time - I think.

[ffeu]

@kroikie do you think that's ok?

[kroikie]

Yes that look good to me.

[ffeu]

OK, it's done! 👍

[kroikie]

Much appreciated! Thank you.